The state's consumer advocate is asking utility regulators to investigate why electric customers in Coventry are reporting trouble getting lower rates that the town negotiated with a power supplier through a municipal marketing program.

The Office of the Consumer Counsel called on the state Public Utilities Regulatory Authority to look into the marketing and customer service of Direct Energy Services, a Connecticut-licensed electricity supplier that is already under investigation by state regulators for questionable marketing practices.

In Coventry, town officials have for the past three years negotiated an agreement with Direct Energy to name it as the town's "preferred" supplier, giving the company exposure from the town in exchange for a lower electricity rate, usually a cent or two below the utilities' standard service offers.

Since then, state officials have heard complaints from residents claiming: they were signed up and never received the discounted rate; they had immense difficulty signing up for the program; or they signed up, received the preferred rate, then were dropped from the lower rate after a few months.

At one point, the complaints prompted Town Manager John Elsesser to write to Direct Energy reps: "Word is spreading that the town program is a 'Bait and switch' and this needs to be addressed NOW."

Direct Energy released a written statement Tuesday that said the issues raised by the consumer counsel are "part of an existing investigation already underway with the [PURA] ... in which we've been fully cooperating."

"We take any and all issues regarding our customers and our services seriously, as proven by our immediate response to the ongoing PURA investigation," Direct Energy said. "We are committed to our customers in Connecticut and are addressing this issue as expeditiously as possible.

Consumer Counsel Elin Swanson Katz said in a written statement that from the "number of complaints we've received, we're concerned that there was either a deliberate attempt to 'bait and switch' with a higher price, or gross incompetence in administering Direct Energy's contract with Coventry's customers."

Her office is asking that regulators look at Direct Energy's municipal programs in other towns, including Bolton, Marlborough and Hampton.

"We simply cannot tolerate these kinds of actions in the energy market in Connecticut. Electricity is an essential need and we need to make sure customers are treated fairly and receive the price they are promised," Katz said.